Update on the biologic effects of macrophage colony-stimulating factor.

Macrophage colony-stimulating factor (M-CSF) is critically involved in the survival, proliferation, and differentiation of cells of the mononuclear phagocyte system. These cells acquire specialized functions depending on the tissue in which they reside, suggesting that the development of mature phenotypes is determined by the cooperative effect of other growth factors, and also by the various biologically active isoforms of M-CSF which are differentially regulated. Alteration of M-CSF expression is associated with many pathologic processes, implying that the cells of the mononuclear phagocyte system are critical in maintaining the balance between health and disease in conditions such as infertility, osteopetrosis, osteoporosis, atherosclerosis, uremia, and Alzheimer's disease